Question

You have been asked to evaluate the economic implications of various methods for cooling condenser effluents from a​ 200-MW steamelectric plant. There are two basic types of cooling​ towers: wet and dry.​ Furthermore, heat may be removed from condenser water by​ (1) forcing​ (mechanically) air through the tower or​ (2) allowing heat transfer to occur by making use of natural draft.​ Consequently, there are four basic cooling tower designs that could be considered. Assuming that the cost of capital to the utility company is 15​% per​ year, your job is to recommend the best alternative​ (i.e., the least expensive during the service​ life). Further, assume that each alternative is capable of satisfactorily removing waste heat from the condensers of a​200-MW power plant. What noneconomic factors can you identify that might also play a role in the​ decision-making process?

	Wet Tower Mech. Draft	Wet Tower Natural Draft	Dry Tower Mech. Draft	Dry Tower Natural Draft
Initial Cost	$2.7 million	$8.7 million	$4.9 million	$9.0 million
Power for I.D. fans	40 200-hp I.D. fans	None	20 200-hp I.D. fans	None
Mechanical maintnance/year	$0.16 million	$0.10 million	$0.12 million	$0.12 million
Service Life	30 years	30 Years	30 Years	30 Years
Market Value	0	0	0	0
Power for pumps	20 150-hp pumps	20 150-hp pumps	40 100-hp pumps	40 100-hp pumps

100 hpequals=74.6 ​kW; cost of power to plant is 2.2 cents per kWh or​ kilowatt-hour; induced-draft fans and pumps operate around the clock for 365​ days/year (continuously). Assume that electric motors for pumps and fans are​ 90% efficient.

*The AW of Wet​ Tower, Mechanical Draft is ​$______________. ​(Round to the nearest​ dollar.)

*The AW of Wet​ Tower, Natural Draft is ​$___________​(Round to the nearest​ dollar.)

*The AW of Dry​ Tower, Mechanical Draft is $____________​(Round to the nearest​ dollar.)

*The AW of Dry​ Tower, Natural Draft is ​$______________​(Round to the nearest​ dollar.)

*What is the best​ alternative? Choose the correct answer below.

A. Wet​ Tower, Natural Draft

B. Dry​ Tower, Mechanical Draft

C. Wet​ Tower, Mechanical Draft

D. Dry​ Tower, Natural Draft

*Should such​ non-economic factors as operating issues and licensing be taken into​ consideration?

Yes or No

Answer 1